JPH10221283A - Combustion test method for fuel oil using test diesel engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a smoke stain on transparent glass and conduct a continuous test for a long period by adding an oil-soluble alkaline earth metal compound of a specific wt.ppm in an equivalent metal quantity to a fuel oil. SOLUTION: A transparent window made of transparent glass is formed on the inner wall face of a cylinder head or on the tip outer wall face of a piston so that the combustion state in a combustion chamber can be observed in a test Diesel engine for conducting the combustion test of a fuel oil. When the tip face of an endoscope made of a glass fiber is located on this transparent glass, the combustion state in the combustion chamber of the engine can be observed and recorded as an image with a video unit or a camera. When the combustion test of the fuel oil is conducted, an oil-soluble alkaline earth metal compound of 50-1000wt.ppm, preferably 200-500wt.ppm, in an equivalent metal quantity is added to the fuel oil to prevent the occurrence of a smoke stain on the transparent glass.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel oil combustion test method using a test diesel engine.

[0002]

2. Description of the Related Art Conventionally, in order to examine the combustibility of fuel oil for a diesel engine, a test diesel engine is provided with a transparent window made of transparent glass so that the combustion state in a combustion chamber can be observed. Is used. In such an engine, the end face of an endoscope (fiberscope) is made adjacent to the transparent glass, and a flame image in the combustion chamber can be recorded on a video or a camera through the endoscope. When performing a fuel oil combustion test using such a test diesel engine, if the test is performed for a long time, smoke (black smoke) generated by the combustion of the fuel oil causes smoke on the transparent glass. Adheres, making it impossible to see through the combustion chamber. In such a case, it is necessary to stop the engine, remove smoke stains attached to the glass, and then start the engine again to perform a test. Therefore,
Frequent smoke stains on the transparent glass are not preferred.

[0003]

SUMMARY OF THE INVENTION The present invention relates to a fuel oil combustion test method using a test diesel engine having a see-through window made of transparent glass for observing the state of combustion in a combustion chamber. It is an object of the present invention to provide a method for preventing generation of dirt and enabling a continuous test to be performed for a long time.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, when a fuel oil is subjected to a combustion test using a test diesel engine having a see-through window made of transparent glass for observing combustion in a combustion chamber, an oil-soluble alkaline earth is contained in the fuel oil. There is provided a fuel oil combustion test method using a test diesel engine, wherein a metal compound is added in an amount of 50 to 1000 ppm by weight in terms of metal to prevent smoke staining of the transparent glass.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A diesel engine (hereinafter simply referred to as an engine) used in the present invention is a test diesel engine for performing a fuel oil combustion test, and is capable of observing a combustion state in a combustion chamber. In addition, a transparent window made of transparent glass is formed on the inner wall surface of the cylinder head or the outer wall surface of the tip of the piston. A test diesel engine having such a structure is conventionally known. In this test engine, the end surface of an endoscope (fiberscope) formed by using glass fiber in the transparent glass is positioned to observe the combustion state (eg, flame) of fuel in the combustion chamber of the engine. And can be recorded as an image by a video or a camera.

In the present invention, when a fuel oil combustion test is performed using the test engine, an oil-soluble alkaline earth is contained in the fuel oil in order to prevent the generation of smoke stains on the transparent glass. Add the metal compound. In this case, the oil-soluble alkaline earth metal compound includes beryllium,
Organic salts of magnesium, calcium, strontium and barium such as organic carboxylate, organic sulfonate and organic phosphate are included. Preferred oil-soluble alkaline earth metal salts are metal salts of fatty acids such as barium stearate and barium palmitate. In this case, as the fatty acid component in the fatty acid metal salt, it is preferable to use a long-chain fatty acid having 10 to 200 carbon atoms, preferably 20 to 200 carbon atoms.

The amount of the oil-soluble alkaline earth metal compound added to the fuel oil is 50 to 1000 wtp in terms of metal.
pm, preferably 200 to 500 ppm by weight. If the addition amount of the oil-soluble alkaline earth metal compound is larger than the above range, the influence of the alkaline earth metal compound on the combustion characteristics of the fuel oil to be tested becomes too large, and the combustion characteristics inherent in the fuel oil are measured. You will not be able to do it. On the other hand, if it is less than the above range, it becomes impossible to effectively prevent the generation of smoke stains on the transparent glass.

[0008]

Next, the present invention will be described in more detail with reference to examples. Example 1 A test diesel engine having the following characteristics was used. (1) Engine model: OSKA-DH (2) Inner diameter x process: 118 mm x 108 mm (3) Number of cylinders: 1 (4) Displacement: 1181 cc (5) Compression ratio: 20 (6) Combustion system: direct injection collision Diffusion layered air supply system (7) Cooling method: water cooling This engine is made by inserting a transparent glass into the through hole of the cylinder head to make a see-through window, and an endoscope (manufactured by AVL, product name "Endscope") is made in this see-through window. )) Adjacent to each other, so that video shooting of the combustion state in the combustion chamber is possible.

Next, a fuel oil combustion test was performed using the engine. The properties of the fuel oil, the amount of the oil-soluble barium compound added, the operating conditions of the engine, and the status of smoke contamination of the transparent glass are shown below. (1) Properties of fuel oil (i) Cetane index: 60 (ii) Density: 0.827 g / cc (iii) Distillation characteristics IBP: 167 ° C 5%: 196.5 ° C 10%: 205.5 ° C 20%: 224.5 ° C. 30%: 245 ° C. 40%: 259.5 ° C. 50%: 272 ° C. 60%: 281.5 ° C. 70%: 292 ° C. 80%: 302.5 ° C. 90%: 315.5 ° C. 95%: 324.5 ° C EP: 335.5 ° C (2) Engine operating conditions (i) Fuel temperature: 25 ° C (ii) Cooling water temperature: 80 ° C (iii) Lubricating oil temperature: 70 ° C (iv) Inlet air temperature: 25 ° C (v) Inhalation air humidity: 70%

(3) Test Results Barium stearate as an oil-soluble alkaline earth metal compound and 0 to 600 wt ppm as Ba in the fuel oil.
The barium-added fuel oil was used to drive the diesel engine. The smoke stain adhering to the transparent glass 10 minutes after the start of driving of the diesel engine was evaluated by the following three-step method. Table 1 shows the results. ○: Substantially no smoke dirt, and shooting of fuel oil combustion flame is possible. △: Smoke dirt, but shooting of fuel oil combustion flame is possible. ×: Smoke dirt is severe, and shooting of fuel oil combustion flame is possible. impossible

[0011]

[Table 1]

[0012]

As can be seen from the results shown in Table 1, the addition of a small amount of the oil-soluble alkaline earth metal compound to the fuel oil can significantly reduce the smoke stain on the transparent glass, A combustion test can be performed continuously. Therefore, it is not necessary to frequently perform the operation of stopping the engine, removing the smoke stain, and then driving the engine again to perform the combustion test in order to remove the smoke stain on the transparent glass, as in the related art. In addition, a fuel oil combustion test using a diesel engine can be performed smoothly. Moreover, in the case of the present invention,
Since the addition amount of the oil-soluble alkaline earth metal compound is specified to be 1,000 wtppm or less in terms of the metal, the combustion characteristics inherent in the fuel oil can be tested without being particularly affected by the alkaline earth metal. .

Claims (2)

[Claims] In a fuel oil combustion test using a test diesel engine having a transparent window made of transparent glass for observing combustion in a combustion chamber, an oil-soluble alkaline earth metal compound is added to the fuel oil. , 50-1 in metal conversion
A fuel oil combustion test method using a test diesel engine, wherein 000 ppm by weight is added to prevent smoke staining of the transparent glass. 2. The method of claim 1, wherein said alkaline earth metal compound is a barium fatty acid.